Tamping



1967 A. J. GASS 3,358,417

TAMPING Filed Feb. 25, 1965 3 Sheets-Sheet 1 INVENTOR B A. J. GASS A T TORNEVS A. J. GASS 3,358, 11 7 TAMPING Dec. 19, 1967 Filed Feb. 25, 1965 3 Sheets-Sheet 2 v INVENTOR BY A.J. GASS A. J. GASS Dec. 19, 1967 TAMPING 3 Sheets-Sheet 5 Filed Feb. 25, 1965 F llll INVENTOR BY A. J. GASS w da A T TORNEYS United States Patent 3,358,417 TAMPING Andrew J. Gass, Summit, N..I., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Feb. 25, 1965, Ser. No. 435,275 3 Claims. (Cl. 53-124) ABSTRACT OF THE DISCLOSURE member.

This application is a continuation-in-part of application Ser. No. 377,671, filed June 24, 1964.

This invention relates to a method and apparatus for tamping or otherwise compacting a resilient material in a container. In one aspect, this invention relates to a method and apparatus for tamping or otherwise compacting a resilient material in a container which is part of a continuous, high-speed packaging machine.

Oftenti-mes products, such as foodstuifs, which are packaged prior to sale to the consumer are of a resilient or spongy consistency and therefore must be pressed down, tamped or otherwise compacted or compressed in its container before the lid, cover material or other closing means is applied to the opening of the container. The problem of tamping of the contents of the container is very acute in present-day continuous, high-speed, automatic packaging machines wherein the container is filled, its contents tamped and the container closed by a suitable cover material.

Heretofore compaction by vibration of the container, in the case of particulate contents in the container, has not proved adequat apparently because the resilient contents require substantial, positive deformation before relatively permanent compaction and deformation is effected.

Also heretofore in order to keep pace with the fastmoving containers of high-speed packaging machinery, rotary tampers such as a wheel having curved plates fixed around the periphery thereof were employed However, an insuflicient amount of tamping of the contents was effected by these rotary tampers due to an insufficient length of tamping time and due to the compressing mechanism of the curved plates being more that of rolling than that of positive deformation in substantially a single direction.

It was thus found that a substantially unidirectional, e.g. vertical, tamping stroke was necessary to efifect a substantial degree of compaction of the contents. However, it was discovered that in a high-speed packaging machine, i.e. one in which the containers are carrier therethrough at a speed of at least 30 feet per minute, a tamping foot which was inserted into the container to compact the contents thereof would have to move with the container for a distance upwards of to feet before adequate compaction of the contents was effected. Since many packaging machine vary in length from to 50 feet 'total, the addition of 12 more feet solely for a tamping mechanism is not only impractical from an economic point of view but also impossible for those machines which must be employed in relatively small and fixed operating areas of a building.

Quite surprisingly, it has now been found that if the tamping operation is carried out in a manner such that the tamping force is applied to the contents of the container in two separate and distinct tamps during a total time period of from about A to about 5 seconds adequate compaction of the contents is effected in about 2 feet. Additional tamping steps can be added as space and economy permit.

The apparatus for carrying out this invention comprises a support means reciprocably mounted for movement into and out of the interior of a container, said support means carrying a tamping foot or member for compacting the contents of the container and means engaging the support means for reciprocating the support means and for moving the support means along the line of travel of the container. The tamping foot can be of,

any desired configuration but preferably covers substantially all of the opening into and the open area of the container.

Accordingly, it is an object of this invention to provide a new and improved method and apparatus for tamping the contents of a container. It is another object of this invention to provide a new and improved method and apparatus for tamping the contents of a container as it passes through a continuous, high-speed packaging machine.

Other aspects, objects, and the several advantages of the invention will be readily apparent to those skilled in the art from the description, the drawing, and the appended claims.

FIGURE 1 is a diametric view of a high-speed, continuous packaging machine in which the invention can be employed.

FIGURE 2 is a schematic representation of apparatus embodying this invention.

FIGURE 3 is a side view of URE 2.

As illustrated in FIGURE 1, there is provided a chain conveyor 22, provided with one or more chains 21, and traversing sprockets 1 and 1', in such a manner that when pockets are afiixed to the chain they will travel through the full operation of said machine and then be returned to the starting point of the operation for another traverse thereof. Aflixed to conveyor 22 are two parallel rows of bottomless supporting pockets l0 and 11, which pockets contain a central opening 3 adapted to receive and support packages or containers to be filled and sealed by the machine. As shown in FIGURE 1, pocket 11 has mounted on an exterior surface thereof rotating means 24 and 25, hereinafter described relative to FIGURE 5. Means 25 is adapted so as to coact with cam rail 27. Means 24 is adapted to coact with rail 2 and thereby support said pocket on its return travel on the underside of conveyor lane 22 and can be adapted to coact with a supporting rail similar to that shown by reference numeral 2 in FIG- URE 1 to support pocket 11 during any or all of the operations shown as applied to the top surface of conveyor 22.

From the original starting point of the over-all operation the pockets are loaded with empty containers, then pass to a charging area wherein the empty containers are filled with the contents ultimately to be sealed therein. Suitable contents charging apparatus is known to the art the apparatus of FIG- and is depicted in FIGURE 1 by means 31. The charging of the contents may even be done by hand, if desired. After the contents of the containers have been charged thereinto, pockets 10 and 11 can move the containers to a tamping operation, designated by reference letter A, wherein the contents of the containers are adjusted therein. During this adjusting operation, the bottoms of the containers in bottomless pockets 10 and 11 may be supported by any suitable means, if desired.

When the contents of the containers are suitably tam-ped, pockets 10 and 11 move the full containers to the covering operation. Just prior to reaching the covering oper-' ation, pockets and 11 are transversely forced together forming a single lane.

While pockets 10 and 11 are progressing toward the covering operation, roll of cover material 41 is being fed by means of feed rollers 44 in a manner described hereinafter. This step forms a single cover sheet as is represented by reference numeral 48. The single cover sheet 48 is fed into differential feed belt apparatus which comprises belt and opposing belt 59, which can be either a single wide belt or a multiplicity of narrower and parallel but separated belts and can be powered by a single power source, not shown. The differential feed belt apparatus then applies the single cover sheet 48 to at least two of the parallel pockets passing through the cover application apparatus, i.e. pockets 10 and 11. After the single cover sheet 48 has been placed upon the pockets and, therefore, the containers in pockets 10 and 11 by differential belt feeds 55 and 59, said single cover sheet is then temporarily attached or tacked to the containers, for example to the container flanges, of both containers in pockets 10 and 11 while said cover sheet is still a unitary member. The temporary attaching is accomplished by means of at least one heat conducting band 62 which traverses rolls 58, and 61, and is in contact with heating means 63 through rollers 64 and 65. Preferably, there are three tacking bands similar to band 62 made of metal and adapted so that a temporary attachment between the unitary cover sheet 48 and the two containers in pockets 10 and 11 is achieved on at least part of the containers in pockets 1t) and 11, for example on the edge of the container in pocket 11 on the side on which reside members 24 and 25, and on the edge of each container on each side of a line between the two pockets indicated by reference numeral 22'. The unitary cover sheet, after temporary attachment to the two or more containers, is longitudinally severed by means of cutter 66, for example along the line represented by reference numeral 22'.

Pockets 10 and 11 are then moved to a heat sealing operation wherein individual heat sealing heads 89 are moved into contact with at least part of each container, preferably around the periphery of each package or container in each pocket, and are maintained in contact therewith as the pockets continue to move longitudinally toward the end of the conveyor 22. The heating contact time is sufficient to heat seal the individual cover sheet of each container to said package. After traveling with and in contact with the container for a predetermined length of time and travel, each heating head is retracted in a vertical and horizontal manner to reposition same to contact a new container and seal same. More specifically, member 88 supports the multiplicity of heating heads by means of members 93 so that when member 88 is lowered, heating heads are applied not only to the containers in pockets 10 and 11, but also to containers in pockets following pockets 10 and 11. Each heating head 89 is maintained in contact with each package by means of resilient members 94 on each member 93. Each heating head contains therein a heating member 90 which, for example, is connected to a source of electricity by means of wires 91 and 92. Member 88 is supported by travelers 84 and 87 and rotating members 85 and 86. Rotating members 85 and 86 travel along member 76, thus allowing member 88 and its attached heating heads 89 to follow along the travel of each pocket contacted by said heating heads for a distance determined by the relationship of sprockets 79 and 80. When rotating member 86 nears the downstream end of member 76, air cylinder is automatically activated by means not shown to retract member 71 and thereby, by means of clevis 72 and member 73, to rotate bell cranks 74 and 77 about pivots 74' and 77 so that members 75 and 78 are raised, thereby raising member 76. Thus, member 76 is raised by members 75 and 78 and therefore, all heating heads 89 are retracted from contact with each individual container at substantially the same time. While the heating heads are in a vertically retracted position,

member 88 is horizontally retracted to the upstream end of member 76 by means of member83, which is attached at 82 to a chain 81. Chain 81 continuously rotates about sprockets 79 and 80, thereby moving member 88 in a reciprocal manner. Since conveyor 22 is continuously moving, the amount of horizontal retraction of member 88 must be adjusted so that heating heads 89 will move back and downwardly to contact the new containers to be sealed without skipping even though the movement of conveyor 22 has continued.

After the heat sealing operation the sealed containers are passed to a cooling zone wherein are provided individual cooling heads. Each cooling head is of such a configuration that when applied to each individual container a part of the cooling head will come into contact with at least a part of the sealed portion of that container and thereby cool same. The cooling head 110 is maintained in contact with the sealed portion by suitable means.

In FIGURE 2 a drive shaft 111 rotatably supported in a frame and carrying sprockets 112 and 113 drives by sprocket 113 endless chain 114 and by sprocket 112 endless chain 115 (FIGURE 3). A second shaft 116 (FIG- URE 3) carries sprockets similar to and opposed to sprockets 112 and 113 for chains 114 and 115 to traverse when thcy reach the opposite end of the apparatus. One such sprocket 117 is shown in FIGURE 3.

Chains 114 and 115 carry a plurality of support members 118 by bolts 119 and 120. A transverse member 121 joins opposing plates 118 on chains 114 and 115. Extensions 122 are fixed to member 121 and both 121 and 122 have apertures 123 passing therethrough. Supporting means 124 is adapted to slidably fit through apertures 123.

Cam follower 125 is supported on plate 126 which plate has apertures 127 therein which apertures are in alignment with apertures 123 when plate 126 is fixed to end 128 of support means 124. Thus, support means 124 and cam follower 125 reciprocate in concert along with support plate 128 which is fixed to support means 124 opposite cam follower 125. Springs 130 encircle support means 124, bear against 122 and 126 and thereby bias follower 125 in the direction of the camming surface to be discussed later. Tamper foot or plate 131 is carried adjacent plate 129 by bolt 132 which s'lidably fits through aperture 133 in plate 129 and screws into threaded aperture 134 of foot 131. Spring 135 fits about bolt 132 and resiliently biases foot 131 away from plate 129.

Two tamper feet 131 and their related apparatus including camming means 136 are shown since the machine of FIGURE 1 employs two parallel rows of pockets. It should be noted that a single tamper foot or several tamper feet and related apparatus and camming means can be employed if desired. It should also be noted that in the cooling zone of FIGURE 1 the identical apparatus disclosed in FIGURE 2 can be employed with the exception that a cooling head such as that disclosed in the parent application identified in the first paragraph of this specification should be substituted for tamper foot 131.

Cam means 136 are fixed to support blocks 137 which in turn carry a shaft 138 upon which member or arm 139 rotates. Member 139 is fixed to a shaft 140 which is rotatably supported in a frame and which in turn is fixed to level 141. The two levers 141 are joined by bar 142 to air cylinder 143 by clevis 144.

Cam means 136 have a notch 145 in a central portion thereof thereby defining two longitudinally, consecuctively aligned and longitudinally spaced-apart camming surfaces 146 and 147 so that follower 125 and therefore tamper foot 131 will be depressed first by camming surface 146, released by notch 145 and then depressed again by camming surface 147. This arrangement effects two consecutive tamps by the tamping foot in a single container as the container passes under the tamping apparatus and the tamping foot moves along with the container. The cam means 136 are maintained in a laterally spacedpart relationship, at least in part, by transverse member 148.

In the operation of this embodiment of the invention a plurality of tamping devices continuously rotate on chains 114 and 115. If it is desired that tamping be effected cylinder 143 is activated so as to cause movement of bar 142 in the direction of arrow 149 thereby moving camming means 136 downward so that cam followers 125 will contact the camming surfaces and move the tamper foot down into a container. When no tamping is desired cylinder 143 is activated so as to move bar 142 in the direction of arrow 150 which movement results in the elevation of cam means 136 out of the reach of cam follower 125 in its most extended position towards the camming surfaces.

FIGURE 3 shows the apparatus of FIGURE 2 wherein a plurality of tamping devices are carried by chain 115 and cam means 136 are in a lowered position. Tamping device 151 is shown with its cam follower 125 in engagement with camming surface 146 results in the introduction of tamping foot 131 into the interior of container 152 as that container passes in the direction of arrow 153 towards a cover material application means such as that shown in FIGURE 1. Tarnping device 154 is shown in its normal uncammed position in which cam follower 125 is urged by spring 124 into a position most closely approaching camming surfaces 146 and 147 of cam means 136.

The power supply for the over-all operation of the machine is preferably a single source connected to the machine and its various drive elements in any suitable manner known in the art. For example, the sprockets which carry chains 114 and 115 are rotated until the tamping feet on the pat of the chains immediately above the conveyor 22 are in alignment with pockets in the conveyor below those tamping feet. The drive shaft which drives the sprockets that carry chains 114 and 115 is then connected to the drive shaft for conveyor 22 by any suitable means such as a shaft coupling so that when conveyor 22 is moved by its drive shaft, chains 114 and 115 are moved at the same speed by their drive shaft and the tamping feet are moved in alignment with the opening in the pockets of conveyor 22. However, if desired, separate power sources can be attached in a known manner to any portion of the machine. For example, separate power sources can be attached to conveyor 22, to-feed rollers 44, the drive roller for band 55 and/or roller 58, to chains 44, 114, 115, and so on; Also, any suitable means known in the at may be utilized on the machine of this invention to render same automatic in its operation. A full and complete disclosure of this packaging machine and its operation can be found in the copending application referred to in the first paragraph of this specification.

According to this invention a resilient material in a container is passed through a tamping or compression zone at a high speed, i.e. at least 30 feet per minute, preferably from about 35 to about 75 feet per minute, wherein at least two consecutive but spaced apart tamping forces are exerted upon the contents of a container during a total time period of from about A to about 5, preferably from about 2 to about 4 seconds. Generally, the two or more tamping strokes will consume about equal portions of the total time period. Preferably, the first tamping stroke applies a compression or compacting force for at least about one-half the total time period while the second tamping stroke applies a compressive or compacting force for at least one-half of the remaining time in the total time period. The time required for the withdrawal and reapplication of the tamping force between first and second tamps comes from the remaining time in the total time period allowed for the second tamp and can vary from an almost infinitesimally small time to about but less than one-half of the remaining time in the total time period after the first tamp is completed.

when the compressed surface The magnitude of the tamping force applied will vary widely depending upon the amount, type, consistency and the like of the contents of the container as well as the speed and depth of tamping desired but will generally be for each tamp at least preferably at least /1, inch below the desired final surface or level of the container contents. That is to say if the desired final surface is one inch below the original surface of the contents in the container then each tamp should extend at least 1% inches below the original upper surface or highest point of the upper surface of the contents of the container.

By the limited time, consecutive tamp technique of this invention the final surface of the contents in the container is at least one-quarter inch below the original upper surface or the highest point of that upper surface before tamping.

At a speed of about 40 feet per minute a container can be adequately tamped according to this invention in a container travel path length of from about 15 to about 30, generally about 20, inches. With a resilient material as defined in the next paragraph which is in a particulate form having an average maximum dimension of from about to about 4 of an inch, compaction causing an original surface level depression of at least of an inch is effected level is about of an inch below the top of the opening of the container and the container holds from about 5 /2 to about 6 /1 ounces of product.

Generally, the method of this invention is applicable to any solid, resilient or spongy material which upon the application of a substantially unidirectional compressive force to at least one surface thereof undergoes both plastie and elastic deformation so that upon release of the compressive force the material tends to spring back towards its original surface level before compression, but terminates the springing back at a point intermediateof the original surface level and the lowest surface level point reached during the application of the compressive force. The material can either be present in the container in the form of a single block or in particulate form. Generally, these materials include particulate and block foodstuffs that have a high moisture and/or dough, flour and the like content, meat or mixtures of meat with other foodstuffs and the like, both block and particulate form, ductile plastics and rubbers such as formed plastic materials, porous and/ or malleable metal particles and the like. The size of the product particles that can be employed can vary widely but will generally be those having a maximum dimension of from about-% to about 12 or more inches. The container can be formed of any conventional container material which is preferably substantially nonyielding in the tamping process but if of a yielding type of material is supported so as to be substantially nonyielding during the tamping period. Suitable materials include homo and copolymers of 2 or more monomers of mono l-olefins, e.g. ethylene, propylene, and the like, aromatics, esters, amides and the like.

Example A product comprising moist compacted particles of a mixture of soybean meal, meat and bone meal, starch, corn, beef tallow, dried whey product, rind and various preservatives, oils and the like varying in size from about A to about of an inch in their largest dimension is poured into a thermo formed, high-density polyethylene container about 4% inches wide, 5% inches long, and 1% inches deep having an average wall thickness of about 10 mils to the extent that the product is piled from /3 to A of an inch above the top of the container. The filled container is moved past a tamping apparatus similar to that of FIGURE 2 at a rate of about 40 feet per minute. A single tamping stroke is applied to the contents of the container, the stroke being sufiicient in magnitude to force the product to a level inch below the top of the container. In order to achieve compaction of the product in the container so that'the final surface of the product is about inch below the top of the container, the tamping force is applied to the product for a total time period of about seconds. This time period requires the use of about 10 to 12 feet of conveyor line since the container will move that far during that period of time.

When the method of the next preceding paragraph is employed utilizing in lieu of a single applied tamping force two consecutive and spatially-separated tamps in a total time period of about 3 seconds, the product was compacted to a final surface level below the top of the container in about 2 feet of travel of the container.

Thus, from the above it can be seen that the use of consecutive tamps in a limited time period effected the desired degree of tamping in about 2 feet of conveyor line as opposed to 10 to 12 feet of conveyor line with a single, long time period tamp.

Reasonable variations and modifications are possible within the scope of this disclosure without departing from the spirit and scope of the invention.

I claim:

1. In a high-speed tamping device at least one cam means having at least two consecutive spaced-apart cam surfaces, a support member, support means reciprocably carried by said support member for moving towards and away from the cam surfaces of said cam means, a cam follower fixed to said support means, a resilient means carried by said support means and engaging said cam follower, said resilient means being biased so as to urge said cam follower towards said cam surfaces of said cam means, a tamping foot resiliently carried at the opposite end of said support means from said cam follower so that reciprocation of said support means by coaction of said cam follower with said camming surfaces causes a similar reciprocal movement of said tamping foot, said tamping foot being biased away from said support means, continuous conveyor means carrying said support member, means for driving said conveyor means thereby causing engagement of said cam follower with and along the length of said cam surfaces and means for moving said cam away from the line of travel of said cam follower thereby preventing any coaction of said follower with said cam means, said means for moving said cam including a rotatable shaft having an arm fixed thereto, the end of said arm opposite to the fixed end thereof being rotatably attached to said cam means and means for rotating said shaft thereby moving said cam means in either of two directions.

2. In a high-speed packaging machine comprising a conveying means for consecutively moving at least parallel and transversely spaced-apart pocket means for supporting containers therein past a container filling means, a cover material application means, and a sealing means, and wherein said machine includes means for transversely forcing the parallel pockets together prior to passing of same past said cover material application means, a cam means having at least two consecutive spaced-apart cam ment toward and away from said cam means and resilient- 1y biased toward said cam means, a cam follower carried on said sup-port means, a tamping foot resiliently carried on said support means opposite said cam follower and biased away from said support means, means for moving said cam follower into engagement with and along the cam surfaces of said cam means, and means for moving said cam means away from said cam follower so that engagement thereof is prevented.

3. In a packaging machine comprising a conveying means for consecutively moving at least two parallel and transversely spaced-apart pocket means for supporting containers therein past a container filling means and a cover material application means, at least one cam means having at least two longitudinally consecutively aligned and longitudinally spaced-apart carn surfaces, a support member, support means reciprocably carried by said support member for moving towards and away from the cam surfaces of said cam means, a cam follower fixed to said support means, a resilient means carried by said support means and engaging said cam follower, said resilient means being biased so as to urge said cam follower towards said cam surfaces of said cam means, a tamping foot resiliently carried at the opposite end of said support means from said cam follower so that reciprocation of said support means by coaction of said cam follower with said camrning surfaces causes a similar reciprocal movement of said tamping foot, said tamping foot being biased away from said support means, continuous conveyor means carrying said support member, means for driving said conveyor means thereby causing engagement of said cam follower with and along the length of said cam surfaces and means for moving said cam away from the line of travel of said cam follower thereby preventing any coaction of said follower with said cam, said means for moving said cam including a rotatable shaft having an arm fixed thereto, the end of said arm opposite to the fixed end thereof being rotatably attached to said cam means, means for rotating said shaft thereby moving said ca'm means in either of two directions, and means for transversely forcing said parallel pockets together prior to passing of same past said cover material application means.

References Cited UNITED STATES PATENTS 2,387,240 10/1945 Borg 141-80 2,567,052 9/1951 Carruthers 14112 2,603,927 7/1952 Grey 53-124 2,837,127 6/1958 Luther 141-83 X 3,063,390 11/ 1962 Frank.

TRAVIS S. MCGEHEE, Primary Exammer.

R. L. FARRIS, Assistant Examiner, 

2. IN A HIGH-SPEED PACKAGING MACHINE COMPRISING A CONVEYING MEANS FOR CONSECUTIVELY MOVING AT LEAST PARALLEL AND TRANSVERSELY SPACED-APART POCKET MEANS FOR SUPPORTING CONTAINERS THEREIN PAST A CONTAINER FILLING MEANS, A COVER MATERIAL APPLICATION MEANS, AND A SEALING MEANS, AND WHEREIN SAID MACHINE INCLUDES MEANS FOR TRANSVERSLY FORCING THE PARALLEL POCKET TOGETHER PRIOR TO PASSING OF SAME PAST SAID COVER MATERIAL APPLICATION MEANS, A CAM MEANS HAVING AT LEAST TWO CONSECUTIVE SPACED-APART CAM SURFACES, SUPPORT MEANS RECIPROCABLY MOUNTED FOR MOVMENT TOWARD AND AWAY FROM SAID CAM MEANS AND RESILIENTLY BIASED TOWARD SAID CAM MEANS, A CAM FOLLOWER CARRIED ON SAID SUPPORT MEANS, A TAMPING FOOT RESILIENTLY CARRIED ON SAID SUPPORT MEANS OPPOSITE SAID CAM FOLLOWER AND BIASED AWAY FROM SAID SUPPORT MEANS, MEANS FOR MOVING SAID CAM FOLLOWER INTO ENGAGEMENT WITH AND ALONG THE CAM SURFACES OF SAID CAM MEANS, AND MEANS FOR MOVING SAID CAM MEANS AWAY FROM SAID CAM FOLLOWER SO THAT ENGAGEMENT THEREOF IS PREVENTED. 